<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div id="app">
    <div>
      <span>全选:</span>
      <input type="checkbox" v-model="full" />
      <button @click="fn">反选</button>
      <ul>
        <li v-for="item in arr" :key="item">
          <input type="checkbox" v-model="item.checked" />
          <span>{{item.name}}</span>
        </li>
      </ul>
    </div>
  </div>
  <script src="./vue-2.7.14.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        arr: [
          {
            name: "猪八戒",
            checked: false,
          },
          {
            name: "孙悟空",
            checked: false,
          },
          {
            name: "唐僧",
            checked: false,
          },
          {
            name: "白龙马",
            checked: false,
          },
        ],
      },
      computed: {
        full: {
          get() {
            return this.arr.every(item => item.checked)
          },
          set(value) {
            return this.arr.forEach(item => item.checked = value)
          }
        }
      },
      methods: {
        fn() {
          this.full = !this.full
        }
      }
    })
  </script>


</body>

</html>